From 337960a6d1616a4248630628d6f5ff21d062483b Mon Sep 17 00:00:00 2001
From: Mike Farah <mikefarah@gmail.com>
Date: Tue, 25 Mar 2025 15:34:01 +1100
Subject: [PATCH] Fixing add when there is no node match #2325

---
 pkg/yqlib/operator_add.go      | 10 ++++++++--
 pkg/yqlib/operator_add_test.go |  9 +++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/pkg/yqlib/operator_add.go b/pkg/yqlib/operator_add.go
index 6f2322bc..044fe4a0 100644
--- a/pkg/yqlib/operator_add.go
+++ b/pkg/yqlib/operator_add.go
@@ -39,13 +39,19 @@ func toNodes(candidate *CandidateNode, lhs *CandidateNode) []*CandidateNode {
 func addOperator(d *dataTreeNavigator, context Context, expressionNode *ExpressionNode) (Context, error) {
 	log.Debugf("Add operator")
 
-	return crossFunction(d, context.ReadOnlyClone(), expressionNode, add, false)
+	return crossFunction(d, context.ReadOnlyClone(), expressionNode, add, true)
 }
 
 func add(_ *dataTreeNavigator, context Context, lhs *CandidateNode, rhs *CandidateNode) (*CandidateNode, error) {
 	lhsNode := lhs
 
-	if lhsNode.Tag == "!!null" {
+	if lhs == nil && rhs == nil {
+		return nil, nil
+	} else if lhs == nil {
+		return rhs.Copy(), nil
+	} else if rhs == nil {
+		return lhs.Copy(), nil
+	} else if lhsNode.Tag == "!!null" {
 		return lhs.CopyAsReplacement(rhs), nil
 	}
 
diff --git a/pkg/yqlib/operator_add_test.go b/pkg/yqlib/operator_add_test.go
index d65deee8..93f0bb89 100644
--- a/pkg/yqlib/operator_add_test.go
+++ b/pkg/yqlib/operator_add_test.go
@@ -310,6 +310,15 @@ var addOperatorScenarios = []expressionScenario{
 			"D0, P[], (!!map)::a: !cat Saturday, 15-Dec-01 at 6:00AM GMT\n",
 		},
 	},
+	{
+		skipDoc:        true,
+		description:    "Add to empty",
+		subdescription: "should behave like null",
+		expression:     `.nada + "cat"`,
+		expected: []string{
+			"D0, P[], (!!str)::cat\n",
+		},
+	},
 	{
 		description:    "Add to null",
 		subdescription: "Adding to null simply returns the rhs",